JERUSALEM — Climate change isn’t just melting glaciers and drying rivers—it’s draining dairy output, too. A major new study from researchers in Israel and the United States finds that heat stress triggered by rising global temperatures is significantly reducing milk production worldwide, even on cutting-edge farms equipped with modern cooling systems.
Led by teams from Hebrew University of Jerusalem, Tel Aviv University, and the University of Chicago, the peer-reviewed study published in Science Advances reveals that just one day of extreme heat can cut a dairy cow’s milk output by up to 10%, with aftershocks that last more than a week.
“Even the most high-tech, well-resourced farms are deploying adaptation strategies that may be an insufficient match to climate change,” said Dr. Eyal Frank, assistant professor at the University of Chicago and co-author of the study.
(Source: Science Advances, May 2025 edition)
When Cooling Isn’t Enough
The study draws on 12 years of production data from over 130,000 cows across Israel—home to some of the most technologically advanced and efficient dairy farms in the world. Despite the widespread use of fans, misting systems, and water sprinklers, researchers found these cooling techniques only partially offset heat-related losses.
Instead, milk output plummeted sharply when wet-bulb temperatures—a combined measure of heat and humidity—exceeded 26°C (78.8°F). In these conditions, cows took up to 10 days to return to baseline production levels.
“Climate change will have wide-ranging impacts on what we eat and drink—including that cold glass of milk,” Frank said.
(Source: Science Advances; TPS Israel News Service)
Why Israel’s Cows Matter Globally
While the study focuses on Israeli dairy farms, its implications extend far beyond. According to lead author Dr. Ram Fishman, an associate professor of public policy at Tel Aviv University, Israel serves as an ideal “testbed” due to its diverse geography and advanced monitoring systems.
“Israeli farms are scattered across different climates—from Mediterranean to arid—and they’re already deploying the best technology available,” Fishman said. “If we’re seeing significant losses here, it’s a clear warning for other nations.”
(Source: Tel Aviv University press briefing, June 2025)
Among the countries likely to be most affected:
- India and Pakistan – the world’s top milk producers by volume
- Brazil and China – large-scale producers facing rising humidity
- United States – especially states like Texas and California, where extreme heat is growing more common
Without intervention, these nations could see daily losses of 3.5–4% per cow by mid-century, the study warns.
More Than Just Cooling: A Call to Policy Action
Published in Science Advances, the study concludes that current heat mitigation methods will not be enough to prevent ongoing declines in milk production. The researchers recommend a more comprehensive strategy that includes:
- Breeding for heat-resistant livestock
- Improved farm infrastructure and shading systems
- Nutritional supplements to reduce heat stress
- Long-term climate adaptation plans across the dairy supply chain
“This isn’t just about cow comfort—it’s about global food security,” the authors write. “Milk is a key protein source in developing countries. These losses could impact nutrition at scale.”
(Source: Science Advances, DOI: 10.1126/sciadv.climilk.2025)
